DHCPD: One interface serving two subnets

[huntkey]

Hi experts,

I am trying to provide dynamic IP addresses for Avaya phones. They are on a different VLAN than the server. I have configured my Cisco switch with ip-helper configuration to relay the DHCP requests from the phone to the server. Here is my dhcpd.conf file:

authoritative;
ddns-update-style ad-hoc;
option IP-Telephone code 176 = string;
omapi-port 7911;

class "avaya"
{
match if ( substring (hardware, 1, 3) = 00:04:0d );
}

shared-network eth1
{
option domain-name "xxx.net";
option domain-name-servers 4.2.2.1;
default-lease-time 88200;
max-lease-time 88200;

subnet 172.17.0.0 netmask 255.255.0.0
{
pool {
deny members of "avaya";
range 172.17.1.10 172.17.199.254;
option broadcast-address 172.17.255.255;
option routers 172.17.1.1;
option subnet-mask 255.255.0.0;
}

pool {
allow members of "avaya";
range 172.17.200.1 172.17.200.255;
option broadcast-address 172.17.255.255;
option routers 172.17.1.1;
option IP-Telephone "L2QVLAN=101,MCIPADD=172.30.1.100,L2Q=1,L2QAUD=5,L 2QSIG=5,TFTPSRVR=172.30.1.1,VLANTEST=0";
option subnet-mask 255.255.0.0;
}
}

subnet 192.168.1.0 netmask 255.255.255.0
{
range 192.168.1.10 192.168.1.250;
option broadcast-address 192.168.1.255;
option routers 192.168.1.254;
option subnet-mask 255.255.255.0;
}
}


I want my phones to get 192.168.1.x IPs however the server keeps trying to assign it the 172.17.x.x IP. Here is the debug from dhcpd -d -f:

DHCPDISCOVER from 00:04:0d:9d:0a:3f via 192.168.1.254
DHCPOFFER on 172.17.200.255 to 00:04:0d:9d:0a:3f (AVA9D0A3F) via 192.168.1.254

Where did I do wrong? Thanks!

[Lazydog]

Could it be because you have configure that pool to allow "avaya"? Have you tried to move all the Phone information to the 192.168 subnet and comment it out of the 172.17?

[huntkey]

Hi Lazydog,

Thanks for reply! I just updated my config to the following but I still got the same result...

shared-network eth1
{
option domain-name "globalsuite.net";
option domain-name-servers 4.2.2.1;
default-lease-time 88200;
max-lease-time 88200;

subnet 172.17.0.0 netmask 255.255.0.0
{
range 172.17.1.10 172.17.199.254;
option broadcast-address 172.17.255.255;
option routers 172.17.1.1;
option subnet-mask 255.255.0.0;
}

subnet 192.168.1.0 netmask 255.255.255.0
{
range 192.168.1.10 192.168.1.250;
option broadcast-address 192.168.1.255;
option routers 192.168.1.254;
option subnet-mask 255.255.255.0;
}
}

Is there any special option that I have to set for it to recogonize that the request is from different VLAN/IP range?? Thanks!

[Lazydog]

Take a look at this WEB Page.
I understand it is for Nortel but it might give you some ideas.

[huntkey]

Take a look at this [I
I understand it is for Nortel but it might give you some ideas.

Thanks Lazydog... I actually know how to setup options. The problem now is not only specific to phones, but also to normal laptops as well. I plug a laptop in the switch on VLAN 101 but it's getting IP on subnet of VLAN 17, which is the VLAN that the server eth1 is plugged in... However I did define two subnets of both VLANs under "shared-network eth1". Any ideas, Thanks!

[Lazydog]

Have you looked at my original comment? Keep the class defined and allow it to only access he 192.168.*.* pool.